1. Field of the Invention
The present invention relates to an electric apparatus with a foreign matter detection panel.
2. Description of the Related Art
A manufacturing equipment such as a machine tool, a robot, and a coating machine is installed in the factory and the like, where products are manufactured. The manufacturing equipment comprises an electric motor for moving a predetermined part, and an electric apparatus for driving the electric motor. For example, the machine tool comprises a motor for rotating a tool or moving a work, a servo amplifier for driving the motor, and a numerical control apparatus which controls the servo amplifier.
Inside the factory, foreign matter such as dust and liquid may be suspended in the air. For example, cutting fluid for cooling and lubrication of the work is often used for processing with the machine tool. A door is provided to a processing chamber where the work is processed. When the door is opened, splashes or mist of the cutting fluid may be emitted to the outside of the machine tool, instead of remaining inside the machine tool. In addition, metal dust produced during the processing may be emitted to the outside of the machine tool.
An electric component such as the servo amplifier and the numerical control apparatus is installed inside a sealed casing. However, when a door of the casing is opened, a foreign matter suspended in the air may intrude into the inside of the casing. Otherwise, when the casing is not completely sealed, the foreign matter intrudes into the inside of the casing.
Japanese Unexamined Patent Publication No. 10-239374A discloses an insulation deterioration detection device which detects insulation deterioration in a printed circuit board. It is disclosed that electrodes are provided all over the printed circuit board in the insulation deterioration detection device, so as to immediately detect the insulation deterioration when the deterioration takes place at least at one location of the printed circuit board.
Japanese Unexamined Patent Publication No. 61-239322A discloses a touch panel device employed in a display device. This document discloses a technique of identifying a coordinate of a position pressed by a person with a finger, utilizing a surface acoustic wave.